Benefits and Side-Effects of Gastric Bypass Surgery

Gastric bypass surgery bypass is a common and effective procedure. Most people who are seriously overweight can undergo a successful gastric bypass surgery and don't experience negative consequences by always following their doctor's instruction. 
Benefits and Side-Effects of Gastric Bypass Surgery

Last update: 27 April, 2021

The procedure is ideal for people who are obese that have tried dieting and got negative results. It’s also a highly recommendable surgery for people who have severe obesity because losing weight can be a solution to problems related to

  • joints
  • the back
  • circulation
All surgical interventions imply secondary effects and risks, however in regard to gastric bypass surgery, not undergoing the procedure could lead patients to illnesses related to being overweight.
The website Obesidad UC states that gastric bypass surgery is, “the most common surgery for obesity in Chile and all over the globe.

In regard to the success this operation could bring, Obesidad UC affirms that, “it has a high success rate from 60% to 70% weight loss in one year and it also significantly improves other related health conditions.

Benefits of undergoing gastric bypass surgery

A thin woman standing in a large pair of jeans.

  • It’s a very effective surgery for fighting obesity.
  • Patients can lose up to 70% of their body weight. They normally lose the weight over a time period of 6 to 12 months. Many people, however, continue losing weight even after 24 months of the surgery.
  • Recovery time is quick and free of problems. Patients usually are discharged after 3 days and are able to return to their normal life within 8 to 10 days after surgery.

As with all surgical interventions, it implies certain short- and long-term risks depending on the patient. Undergoing a gastric bypass operation is one of the best options for losing weight effectively and safely.

You should seek out an experienced surgeon to perform the operation, to advice you on following a suitable diet and healthy lifestyle habits. 

Read this article too: 5 Drinks to Help You Lose Weight

Side effects

Side effects or adverse effects are those that occur when the patient doesn’t comply with the dietary rules and doesn’t follow all the care recommended by the treating physicians, such as the following.

1. Nutrient deficiencies

After the procedure, a part of the small intestine doesn’t receive essential nutrients (iron, calcium), thus the body doesn’t absorb them. Therefore, the body will experience a deficiency of those nutrients, which could result into other problems such as anemia or osteoporosis. Therefore, it is important to take vitamins to nourish these deficiencies.

2. Malnutrition

Due to the body failing to receive all necessary nutrients, it becomes more vulnerable to all kinds of infections, which in turn causes the immune system to weaken.

3. Dumping syndrome

This syndrome is a stomach condition that appears around 20 minutes after eating. It causes cramps and nausea, which is due to the fats from foods that enter the intestine. It also causes irritation and an abrupt widening of the intestine, which turns into all types of problems such as cramps and soft stools.

This discomfort occurs when the patient has eaten fats or sweets in excess, that is, when they haven’t complied with the dietary indications. It’s important to gradually change foods and choose the healthiest and most natural ones; the more natural they are, the less adverse effects will occur in the digestion.

4. Intestinal obstruction

Patients might suffer from intense cramping, abdominal pain along with the feeling constipated. In surgery, the practitioner might unintentionally move a piece of the bowel into an open area; however, the chances of this surgical error are low.

Recommendations to follow post-intervention

A woman having a bowl of soup.

  • Follow the liquid diet your medical specialists recommended you. Include solid foods gradually into your diet.
  • Follow all of your doctors’ instructions. Your recovery will be fast and simple.
  • Take vitamins and other nutritional supplements due to the changes in your digestive tract.

Get knowledgeable about the matter before undergoing any kind of intervention. Likewise, doctors study each particular case and indicate the best option for them.



  • Díez del Val, I., Martínez-Blázquez, C., Valencia-Cortejoso, J., Sierra-Esteban, V., & Vitores-López, J. M. (2004). Bypass gástrico. Cirugia Espanola. https://doi.org/10.1016/S0009-739X(04)72311-8
  • Garciacaballero, M., Reyes-Ortiz, A., Toval, J. A., Martinez-Moreno, J. M., & Miralles, F. (2014). Development of type 2 diabetes mellitus thirty-one years after Billroth II in a patient asking for diabetes surgery. Nutricion Hospitalaria. https://doi.org/10.3305/nh.2014.30.1.7472
  • Rubio, M. A., Rico, C., & Moreno, C. (2005). Nutrición y cirugía bariátrica. Supl Rev Esp Obes. https://doi.org/10.1016/S0737-0806(02)70026-9
  • Herrera, M. F., Zarain, A., & Arceo, R. (2005). Cirugía bariátrica. Revista de Gastroenterología de México. https://doi.org/10.1016/S0716-8640(12)70296-1